Method of and apparatus for conserving cocoons of silk-producing insects



a. o. HURS'T IETHOD'OF AND APPARATUS FOR CONSERVING COOOONS OF SILK PRODUCING INSECTS Filed Sept. 20, 1924 March 12, 1929.

75a, Mann/Ty UNIT I IlII/IIIII; 7/11! Patented Mar. 12, 1929.

1,704,972 UNITED STATES PATENT oFFics:

GLENN D. HURST, OF LOS ANGELES, CALIFORNIA.

METHOD OF AND APPARATUS FOR CONSERVING COCOONS F SILK-PRODUCING INSECTS.

Application filed September 20, 1924. Serial No. 738,886.

Silk-producing insects, particularly the Bombyx mori, or mulberry silk worm, are metamorphosing insects performing their life cycle in four changes, viz, the egg, the

larvae, the chrysalide and the adult or moth.

At the conclusion of the larval period, the insect spins a cocoon about its body, the natural purpose of which is to provide a protected place or housing in which to carry on the transformation from larvae to moth.

It is this filament which is recovered from the cocoon that provides the silk textile fiber.

Inthe art of making raw silk thread, the

filament of a single cocoon is unraveled and forms one continuous strand. This strand or filament is united with other like filaments to make a composite orv aggregate thread of sufficient strength for commercial use.

In the natural evolution of the insect, to adult moth, the larva is transformed within the cocoon to a chrysalide, which is the rudimentary form of the adult moth. The chrysalide then continues its development to the adult moth, and the moth secretes a fluid which decomposesthe filament wall of the cocoon and then emerges from the cocoon shell.

The emergence of the moth destroys the cocoon so far as the recovery of a continuous filament from the cocoon is concerned.

The practice of the industry for centuries has been to destroy the life of the insect in its chrysalide form by suffocating it with heat, so that the cocoon can be utilized for reeling. In this way the entire filament is recovered.

The application of heat for this purpose hardens the gum of the filament and produces many defects which are present in raw thread and are detrimental to the man ufacture of yarns or fabrics.

It is the purpose of my invention'to provide a method of conserving the cocoon for panying drawing forming a partof this ap-.

plication in which The figure shows a building in. which an apparatus is disposed for arresting the development of the insects. I

In order to arrest and then suspend the moth development of the cocoons imme diately following the period of metamorphosis, and with the object of preventing the emergence of the moth from the cocoon shell and thus to conserve the cocoon in its native state with a fresh, unbroken filament for reeling into raw silk skein, I have provided a building V having walls which are insulated against heat so that the exterior temperature will have-no effect on the interior temperature. This building is constructed to provide a hermetically sealed-chamber 73 in. which the temperature, humidity and pressure of air is controlled and maintained. A refrigeration unit 74 reducesto a predetermined degree the temperature of a current of air supplied thereto from a humidity unit 7 5 in communication with atmosphere and withdrawn therefrom at a predetermined and fixed volume and velocity by a mechanical air compressor 7 6, the air being ultimately delivered to the chamber 7 3 under a pressure which can be controlled to obtain and maintain a. predetermined pressure in the chamber. Within the chamber 73 are hampers 73 in which the cocoons are placed,

the hampers being formed of wire screen, as indicated, to allow free circulation of air therethrough. V

The building V is provided with a second and larger chamber 7 7 in which the cocoons are adapted to be stored after being removed from the chamber 7 3. In this, storage chamber 77, the temperature, humidity and circulation of air is also controlled and maintained. For this purpose, a heating unit 78 communicates with the refrigeration unit 74 so as to increase the temperature of the air Withdrawn from the latter and delivered to the storag chamber by a blower 7 9 in communication with the heating unit.

My method of arresting and suspending the development of themoth, following the period of metamorphosis, is carried out with the above apparatus, and the methodv has undergone a change in bodily structure which is completed by an invisible mo-ult within the cocoon and at the conclusion of which the insect emerges from the skin the larva of its fifth age as a chrysal'is. Upon completion of the metamorphosis, and before the process of transformation to the moth has progressednraterial-ly, I. remove the cocoons to the chilling chamber 73, where the cocoons are subjected to a chilling process in which the air of a temperature of 40 degrees Fahrenheit. The cocoons are subjected to this chilled air under a pressure of approximately six inches, as indicated by the measuring water column, for approximately one-half hour. This pressure causes the air to immediately penetrate the interstices of the cocoon mesh, and to arrest the develop ment of the chrysalis by rapidly reducing the temperature of the cocoon to the temperature of the chamber 77. The cocoons are then rcmoved'to the storage chamberin which the temperature is maintained at 4 degrees Fahrenheit, with a humidity of ap proximately 75 degrees of saturation and. a circulation of new air, and in this environment the chrysales remain dormant, and in this dormant state they are delivered to the filature for reeling.

By the above method and the apparatus to make it effective, the last moult of the insoot, in which the moth emerges from the envelope of the chrysal-is and penetrates the shell of the cocoon, is prevented, and the filamentrof the cocoon is preserved intact; the filaments of the cocoons are preserved in a state of freshness with all the native quali ties that are commercially desirable unimpaired, namely, tenacity, elasticity, suppleness and lustre; the gummy covering of the filament'which fixes it in place in the mesh of the cocoon layers is also maintained in a condition of freshness, which, together with the preserved state of the filament, facilitates the process of reeling and results in useful economies in working the filament from the cocoon into the raw silk skein with a minimum of defects.

Although I have herein shown and described only one main method of arresting the development of the silk worm, and only one form of apparatus by which the method can be performed, it is to be understood that various changes in the method and apparatus can be made herein without departing from the spirit of the invention and the spirit and scope of the appended claims.

I claim: V

l. A method of suspending the moth development of silk producing insects which comprises the subjectionof the cocoons for a predetermined period to cooled air under pressure sufiicient to penetrate the cocoons and reduce the temperature of the chrysalis sufficiently to arrest its development.

2. A method of suspending the moth development of silk producing insects which comprises the subjection of the cocoons for a predetermined period to cooled air under pressure sufficient to penetrate the cocoons and reduce the temperature of the chrysales sufliciently to arrest its development, and then subjecting the cocoons to constantly circulating air at a predetermined increased temperature and predetermined humidity in which the functions of moth development are not resumed.

3. A method of suspending the moth development of silk producing insects which comprises the subjection of the cocoons for a predetermined period to cooled air of predetermined humidity, temperature and pressure, the pressure being sufficient to penetrate the interstices of the cocoon and thus to rapidly chill the chrysalis to arrest its development.

4. A method of suspending the moth development of silk producing insects which comprises the subjection of the cocoons to circulating air of regulated and predetermined humidity and of regulated predetermined tempcrature sufiiciently low to .chiil the ch-rysales and thus to arrest and suspend its development. 1

5. A method of suspending the moth development of silk producing insects which comprises the introduction ofthe cocoons .at the conclusion of the period of pupation into an enclosure or chilling chamber, the sealing of the chamber so that a pressure .of air may be maintained therein, the introductionof air of predetermined temperature snfiiciently low to arrest the development of the moth, and of a degree of humidity to prevent saturation of the silk filament, and the maintenance of these degrees of temperature and humidity under a predetermined low pressure, the exposure of the cocoons to these environments for asufiicicnt. period of time to cause the temperature of the chrys ales to be reduced to approximately the degree of temperature of the air within the chamber, the removal of the cocoons to a storage chamber when the chrysales have been reduced in temperature to the'predeten mined degree, the maintenance within the storage chamberof ,acontinued renewal of fresh air of such a degree of temperature and humidity that the'chrysales will tinue in a state of dormancy, the exposure of the cocoons to these environments for an indefinite period.

6. A method of suspending the moth development of silk producing insects which comprises the introduction of the cocoons at the conclusion of the period of pupation into an enclosure or storage chamber, the maintenance Within the chamber of a continued renewal of fresh air of such a low degree of temperature that the ehrysales will be arrested in development and the saiddevelopment will be indefinitely suspended, and of such a degree of humidity that the filament of the cocoon will be held below the point of saturation, and the exposure of the cocoons to these environments for an indefinite period.

7. The herein describedmethod of arresting and then suspending the moth development of cocoons immediately following the period of metamorphosis, and for preventing the emergence of the moth from the cocoon so as to conserve the cocoon in its native state with a fresh, unbroken filament, which consists in placing the cocoons in a hermetically sealed chamber, while subjecting the same to the free action of humid air at a fixed temperature, velocity and volume, and then removing the cocoons from said chamber and subjecting same to a treatment of refrigeration.

8. The herein described method of arrest-.

ing and then suspending the moth development of cocoons immediately following the period of metamorphosis, and for preventing the emergence of the moth from the cocoon so as to conserve the cocoon in its native state with a fresh, unbroken filament, which consists in placing the cocoons in a hermetically sealed chamber, while subjecting same to the free action of humidair at a fixed temperature, Velocity and volume, and then removing the cocoons from said chamber and subjecting same to a treatment of refrigeration in the presence of controlled temperature, humidity and air in circulation.

9. An apparatus for suspending the moth development of silk producing insects comprising a hermeticallysealed chamber for receiving thecocoons, and means for supplying chilled air under pressure to the chamber.

10. Apparatus of the class described, comprising a hermetioallysealed chamber having means whereby temperature, humidity,

velocity and volume of air is controlled and maintained therein, a second chamber in which cocoons as same are taken from the first chamber, are adapted to be stored, and

vmeans whereby temperature, humidity, ve-

locity and volume of air are controlled in said second chamber.

11. A method of suspending the moth development of silk producing insects, which comprises the subjection of the cocoons for a predetermined period to cooled air, which penetrates the cocoons and reduces the temperature of the chrysalis sufiiciently to arres its development.

12. 'An apparatus for suspending the moth development of silk producing insects, comprising a hermetically sealed chamber for receiving the cocoons and means for supplying chilled air under pressure to said chamber.

GLENN D. HURST. 

